An Editorial by dieselmann
Volume 3; July 99: Synthetic engine oils, lubricants and ELC's
Synthetic lubricants are manufactured from petroleum bases*, as are conventional oils, only they are more refined to increase their durability and resistance to thermal and chemical break down and to increase their lubricity.
*synthetic lubricants are manufactured in part from petrochemicals, which are refined from petrolium
They tend to provide lubrication protection and maintain their fluidity over a wider temperature range--higher as well as lower. Synthetic lubricants are also less likely to vaporize at normal operating temperatures as conventional oils are. The result of this is that they provide greater protection for your vehicle for a longer period of time and can--manufacturers of these products claim--reduce emissions and increase fuel mileage. The offset of this is their increased cost however, in most cases you can safely double the mileage between oil changes.
For those of you wishing to lengthen the service interval between oil changes on your vehicle, you can use a quality synthetic engine oil with the appropriate SAE "weight" and API service rating:
Synthetic transmission fluid and gear lube work in the same way. They are designed to perfrom and protect at a wider temperature range than their conventional equivalent. Ford has always specified using synthetic Mercon--their brand-name for Dextron--in ZF 5 speed transmissions with diesel engines. Synthetic gear lube has become standard in Ford vehicles starting around 1997, and they also recommend using it in any four wheel drive front axle with automatic locking hubs.
However, Ford does not recommend using synthetic or Propylene Glycol coolant in any of their vehicles as they feel it does not provide adequate protection as compaired to Ethylene Glycol. For this reason, if you wish to use an Extended-Life Coolant in your vehicle, ensure that it is Ethylene Glycol-based. Also keep in mind that ELC's require a different conditioner than that used with conventional coolants in diesel engines--check the manufacturer's recommendations.
One inconvenience of using synthetic lubricants, engine oils or ELC's is that to be trully effective they should never be mixed with conventional ones. In fact, when switching to an ELC, all conventional coolant needs to be flushed from the vehicle cooling system. Most repair facilities and parts stores do not carry a full line of synthetics. This may mean that you will need to carry your own supply in case emergency repairs are required.
Amsoil Engine Oil info
Caterpillar ELC information
Shell Oil's product page for info on their Rotella oils and ELC.
Charles David Ledger; dieselmann©1999